package org.apache.lucene.distributed.index;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.distributed.RMI;
import org.apache.lucene.distributed.index.IndexService.IndexListener;
import org.apache.lucene.distributed.index.LuceneClient.LuceneIndex;
import org.apache.lucene.search.MultiSearcher;
import org.apache.lucene.search.Searchable;
import org.apache.lucene.search.Searcher;

/**
 * Enables search over multiple servers.
 *
 */
public class LuceneMultiClient implements IndexListener {
  RMI rmi;
  List<LuceneIndex> clients = new ArrayList<LuceneIndex>();
  volatile MultiSearcher searcher;
  
  public LuceneMultiClient(RMI rmi) {
    this.rmi = rmi;
  }
  
  public void add(InetSocketAddress addr, String indexName) throws Exception {
    LuceneClient luceneClient = new LuceneClient(addr, rmi);
    IndexService indexService = luceneClient.indexManagerService.getIndex(indexName);
    LuceneIndex luceneIndex = luceneClient.getIndex(indexService);
    clients.add(luceneIndex);
  }
  
  private void createSearcher() throws IOException {
    Searchable[] searchables = new Searchable[clients.size()];
    for (int x=0; x < clients.size(); x++) { 
      searchables[x] = clients.get(x).getSearchable();
    }
    searcher = new MultiSearcher(searchables);
  }
  
  public void newSearchable(SearchableService searchableService) throws Exception {
    createSearcher();
  }
  
  public synchronized Searcher getSearcher() throws IOException {
    if (searcher == null) createSearcher();
    return searcher;
  }
}
